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Friday, 10 March 2017

Dynamite Guns: Brilliant Technical Dead-Ends!

A major role is played in the Dawlish Chronicles novel Britannia’s Shark, set in 1881, by an experimental “pneumatic
projector” – essentially a gun from which the projectile is launched by
compressed air. Such weapons were considered very promising in the 1880s and
1890s and indeed the inventor John Phillip Holland, who also features in “Britannia’s Shark”, built a 9-inch
projector into his 1882 Fenian Ram, arguably the first successful submarine.

15-inch Dynamite Gun at Fort Winfield Scott, San Francisco

Though forgotten today, the concept was very attractive in
its own day and the spur to its development was the recent invention of
dynamite, an explosive of considerably greater power than any other previously
available. Filling conventional artillery
shells with dynamite would obviously increase their potency but the concern was
that dynamite was sufficiently unstable as to be incapable of resisting the rapid
acceleration involved in discharge from a conventional gun. A method of
propulsion which would give slower acceleration, but comparable range, was what
was required. The answer was to eject the shell from a giant blow-pipe by means
of compressed air.

There were other advantages. Lighter gauge metal could be
used for the discharge tube than would be needed for a conventional gun-barrel
and larger-calibre weapons could be carried for the same weight. Also the lack
of flame and smoke when the projectile was discharged would reduce visibility,
and chance of location, particularly at night. The greatest potential was as an anti-shipping weapon. A
direct hit would not be necessary if a large enough projectile could be dropped
into the water close to the ship. Exploding underwater, the shock waves would
rupture the hull. Recognition of the effectiveness of below-waterline attack had
already led to the development of the self-propelled torpedo. At a time however
when torpedo speeds, ranges and sizes were still low a pneumatic projector
offered the opportunity of landing a larger charge close to a moving ship more
quickly and accurately, and at greater ranges.

8-inch Zalinski gun on trial - note barrel built up of flanged tubes

Credit for proving the concept went to a Mr.D.M.Melford of
Toledo, Ohio, who demonstrated a 2-inch prototype to the US Military in 1884,
firing a 5-pound solid shot over half-a-mile and driving it through a 26-inch
thick concrete target. Mefford seems to have faded from the scene thereafter
but one of the observers at the trial, an artillery lieutenant called Edmund Zalinski picked up the idea and formed the “pneumatic Dynamite gun Company”. By 1885 Zalinski had an operational prototype
with an 8-inch bore which could fire a projectile with a 100 pound dynamite charge
over two miles. The projector was at least as accurate as conventional cannon
of the same calibre and, though the range was less, could carry a much larger
explosive charge,

The US Navy was now interested – not least because such
weapons could be mounted in smaller, lighter ships. A test in 1887 completely
destroyed a target ship and the publicity this got led to the decision to build
a "dynamite cruiser" armed with three such weapons. Zalinski, by now
US Naval attaché to Russia, returned to supervise development of these
projectors as well as the construction of similar ones for mounting in coastal-defence
fortifications.

USS Vesuvius on contemporary postcard. Note the three black projector barrels on foredeck

The Vesuvius – an
unarmoured 246 ft, 930 ton vessel, with
two 2200 hp engines giving her a top speed of 21 knots – was fitted with three fixed
15-inch bore projectors. To aim them the entire ship needed to be aimed at the target
–this was to prove the main operational drawback – and range was varied by
adjusting air pressure. They offered the capability of hurling quarter-ton
dynamite charges up to a mile, while with a reduced charge of 200 lbs the respectable
range of two and a half miles was achievable. In one test fifteen projectiles
were fired by the Vesuvius in just
over sixteen minutes. The projectiles themselves
looked like huge darts, with sheet meal tails carried on an extensions behind the
charge proper, the fins being angled to as to impart a spin – and stability –
in flight. Once the projectile had dropped into the water, and had begun to sink,
salt-covered fuses were exposed which, when fully exposed to sea-water,
completed an electric circuit and detonated the charge.

15-inch Zalinski projectile - note the twisted fins

USS Vesuvius - the projector barrels could only be aimedby aligning teh ship's bows on the target

Despite extensive trials, which revealed many operational problems,
the Vesuvius
did not enter active service until the Spanish-American War in 1898. She was to
bombard a Spanish fortification at Santiago, Cuba, but the results, though visually
spectacular, seem to have been meagre, doing little more than plough up the fort’s
glacis. She was converted to a torpedo-trials vessel thereafter (an ironic fate,
in that the Zalinski guns once had once promised to replace the torpedo) and, with
her pneumatic projectors removed, she lasted to 1922.

One other Zalinski gun was mounted on a warship. This was a
single 15-inch unit mounted on a Brazilian auxiliary cruiser, the Nictheroy, a 7080-ton (displacement)
Brazilian auxiliary cruiser. She was originally a coastal passenger and cargo operated
under the name El Cid by the Morgan
Lines company. Faced with a large-scale naval mutiny in 1894, the Brazilian
government looked frantically for ships overseas, bought El Cid, and had a
Zalinski weapons similar to those of the Vesuvius
installed. Though she reached Brazil the mutiny was suppressed without the Nictheroy needing to open fire. She was purchased back by the
US Navy at the time of the Spanish-American War and had a worthy career
thereafter in various support roles as the USS Buffalo. She was sold in 1927.

"Battery Dynamite" at Fort Winfield Scott, San Francisco

15-inch Zalinski guns were also evaluated by the US Army’s
coastal artillery, offering enough promise for two such weapons, and a small
8-inch gun, to be mounted Fort Hancock, New Jersey, in 1894. These were
regarded as sufficiently successful for three more 15-inch guns to be located at San Francisco in 1898 to protect the Golden Gate, followed by individual
weapons at Hilton Head, South Carolina
and Fishers Island, New York. in 1901. By
then they were being made obsolete by the development of more stable explosives
– such as cordite – which were stable enough to be fired from conventional guns
over much greater ranges. All US Army batteries were scrapped well before WW1.

The concept still had sufficient promised for John Phillip
Holland, built two 8.4-inch Zalinski guns into the first
commissioned US submarine USS Holland (SS-1), no doubt remembering his first
attempt to do so in the early 1880s. They were however removed afterwards.

USS Holland - note projector tube.The cover is missing, so weapon presumably no longer in use

One other pneumatic gun was to enter service. This was the bizarre
Sims-Dudley gun for use as mobile field artillery. This duty precluded use of steam-driven
compressors, as installed on ships or at fixed shore batteries. Instead, a separate
cylinder was placed below the projector tube and a smokeless-powder charge was
detonated in it to send compressed air – presumably on the other side of a
piston, to the launching tube. This seems to have been an example of having the worst of both
worlds in design terms, and the age-old principle of Occams’s Razor, as valid
in technology as in philosophy, must have been unknown to the inventors. Despite
this the US Army bought sixteen of these guns, firing 2.5 inch calibre,
10-pound projectiles with 5-pound bursting charges. The projectiles seem to
have been smaller versions of the Zalinski missiles, as shown in teh illustration below.

Colonel Theodore Roosevelt and his Rough Riders used a
Sims-Dudley gun during the siege of Santiago. Its greatest advantage appears to
have been its lack of a loud report and the fact that its smokeless-power
charges did not reveal the weapon’s location to the enemy. It seems however to have
been mechanically unreliable. The Sims-Dudley faded from history
afterwards – probably deservedly so!

Though considerable ingenuity was expended in making pneumatic
guns work, and though the American Government was prepared to invest large sums
in their development, they ultimately represented one of history’s technological
dead-ends. The advent of more stable explosives, and of longer-ranged and faster
torpedoes, quickly sidelined them. Pneumatic guns do not however deserve to be
forgotten, and for me, in Britannia’s
Shark, it has been a delight to write about the period when they still held
such promise.

Britannia's Shark

Click on the image below to learn more about Britannia's Shark. This will allow you to read the opening chapters - including the testing of a pneumatic gun.

Download a free copy of Britannia’s Eventide

To thank subscribers to the Dawlish Chronicles mailing list, a free, downloadable, copy of a new short story, Britannia's Eventide has been sent to them as an e-mail attachment.

It always struck me that Jules Verne forgot about the enormous mass of air that would have had to be displaced ahead of the projectile!Interesting that the location chosen for the giant gun was in Florida (possibly near Cape Canaveral?)

About Me

My "Dawlish Chronicles" are set in the late 19th Century and reflect my deep interest in the politics, attitudes and technology of the period. The fifth novel in the series, “Britannia’s Amazon” is now available in both paperback and Kindle formats. It follows the four earlier Dawlish Chronicles, "Britannia's Wolf", "Britannia's Reach”, "Britannia's Shark" and "Britannia's Spartan". Click on the book covers below to learn more or to purchase.
I’ve had an adventurous career in the international energy industry and am proud of having worked in every continent except Antarctica. History is a driving passion in my life and I have travelled widely to visit sites of historical significance, many insights gained in this way being reflected in my writing. I welcome contact on Facebook and via this Blog. My website is www.dawlishchronicles.com and its “Conflict” section has a large number of articles on topics from the mid-18th Century to the early 20th Century.